Why is December 21 important to science?

Answer 1

December 21 is the winter solstice. This is the first day of winter in the Northern Hemisphere, and the shortest day of the year. The earth is tilted approximately 23.5 degrees on its axis. On two days of the year, the equator of the earth is closer to the sun due to this tilt. These days are June 21 and December 21. On December 21, the sun appears to be close to the horizon, resulting in the shortest day of the year. From December 21 onward, days get longer and longer.

In the Southern Hemisphere it is the day with most sunlight.

Answer 2

December 21 is important to science because it marks the winter solstice in the Northern Hemisphere, which is the shortest day and longest night of the year. This event is significant for scientists studying astronomy and the Earth's axial tilt, as well as for cultures around the world that mark this day with various traditions and celebrations. Additionally, the winter solstice has been studied historically as a key indicator of the changing seasons and the movement of the Earth in relation to the sun.